Bill and Hillary Clinton are to money what the Gulf of Mexico is to the Mississippi River: the inevitable destination of a large and never-ending flow, which is sometimes polluted.

The latest example comes in the form of donations of $2.35 million to the Clinton Foundation by the chairman of a Canadian uranium company that needed, and got, U.S. government approval to be taken over by a Russian firm that enjoys the favor of Vladimir Putin.

Maybe you can guess who was secretary of state at the time the State Department reviewed the deal. Oh, and those contributions were not publicly disclosed, reports The New York Times, "despite an agreement Mrs. Clinton had struck with the Obama White House to publicly identify all donors."

Maybe it will all turn out to be innocent, but when you conceal something you had promised to reveal, you invite suspicions. And when you and your husband make King Midas look incompetent at accumulating wealth, you raise the question of whether you have any scruples about how you acquire it.

In her recent political travel, Hillary didn't want to get into questions involving her finances or her husband's, raised in a forthcoming book by Peter Schweizer. "Well, we're back into the political season and therefore we will be subjected to all kinds of distractions and attacks and I'm ready for that," she said dismissively.

But there are types of money she is willing to talk about. On a visit to Iowa, she said, "We need to fix our dysfunctional political system and get unaccountable money out of it once and for all, even if it takes a constitutional amendment."

The declaration might help to inoculate her against investigations of how she and Bill set out to do good and ended up doing well. It's also a gesture of solidarity with the more liberal members of the Democratic Party.

As an indication of the policies that might come to pass in a Clinton administration, though, it should not be taken seriously. Almost any time a politician proposes a constitutional amendment, she is telegraphing that nothing will be done about the problem it addresses.

In the first place, constitutional amendments are extremely difficult to pass. This one faces virtually unanimous opposition among Republicans, who happen to control both houses of Congress and 31 state legislatures. So it has about the same chance of being enacted as Miranda Lambert has of becoming prime minister of Turkey.

Because a campaign finance amendment is not going to happen, Clinton can safely appease those Democrats who favor it without fear of incurring responsibility for its consequences.

But they and others should take this as additional proof that when a conflict arises between the power of government and the liberties of individuals, the former will always take priority with Clinton. The amendment sponsored by Senate Democrats would give public officials broad latitude to police what is said and written about candidates and their policies.

It stipulates that the federal government and the states "may regulate and set reasonable limits on the raising and spending of money by candidates and others to influence elections." As legendary First Amendment lawyer Floyd Abrams testified, the amendment "deals with nothing but political campaign speech. It does not deal with money that is spent for any purpose other than persuading the public who to vote for or against and why."

It presumes that wealthy individuals and corporations can get their way by spending on elections. But in 2010, noted Cato Institute scholar John Samples, 52 Republican challengers beat Democratic House incumbents -- even though 43 of the challengers were outspent.

In 2012, casino tycoon Sheldon Adelson spent $20 million on Newt Gingrich and $30 million on Mitt Romney, both losers. He spent $42 million to support candidates in nine other races, eight of whom failed. Environmentalist billionaire Tom Steyer laid out $74 million in Senate and governors' races and lost more than he won.

Money doesn't buy votes. What it buys is the means to communicate ideas to voters. If those ideas, or the candidates advocating them, aren't compelling, the money is wasted.

If Hillary Clinton were not only cynical but greedy as well, she might actually resent billionaires who squander their fortunes on losing campaigns instead of on, say, speaking fees for members of the Clinton family or donations to the Clinton Foundation.